Last updated: May 2026
Enter any time value and instantly see the equivalent in all other units — from milliseconds to years.
Enter a value in any unit — all other units update live. Covers milliseconds through decades.
Other Unit Converters
Time is one of those things you'd think everyone agrees on — and they do, in principle. The problem is that different fields and contexts use wildly different units for it, and converting between them by hand is exactly the kind of arithmetic that introduces expensive errors.
Payroll and billing. Hourly workers and freelancers live in decimal hours, but clocks display hours and minutes. A consultant who logs 7 hours 45 minutes needs that as 7.75 hours to multiply against their rate. Do that wrong across 200 employees and payroll is a disaster. Billing software makes the same conversion hundreds of times a day.
Project management. Sprint estimates in hours, project timelines in weeks, roadmaps in months and quarters. The moment you need to answer "if each task takes 90 minutes, how many can we fit in a two-week sprint?" you're converting time. Tools like Jira and Asana force you to think in multiple time units simultaneously.
Travel and scheduling. Booking a flight with a 14-hour layover sounds dramatic in hours; it's just over half a day. Time zones add another layer — a 9 AM call in New York is 2 PM in London and 9:30 PM in Mumbai. The underlying math is always hours and minutes converting to and from each other.
Science and computing. Physics works in seconds (and fractions thereof). Computer performance is measured in milliseconds, microseconds, and nanoseconds. Signal propagation, reaction times, API latency, database query speed — none of these make sense without comfortable fluency in small time units. A 250ms delay is a quarter of a second, which is roughly the speed of human reaction. A 2,000ms page load is two full seconds, which is the point at which most users start to lose patience.
| Duration | Hours | Minutes | Seconds | Days | Weeks |
|---|---|---|---|---|---|
| 1 work shift (8 hrs) | 8 | 480 | 28,800 | 0.333 | 0.0476 |
| 1 day (24 hrs) | 24 | 1,440 | 86,400 | 1 | 0.1429 |
| 1 week | 168 | 10,080 | 604,800 | 7 | 1 |
| 1 month (avg) | 730.5 | 43,829 | 2,629,746 | 30.4375 | 4.348 |
| 1 year (365.25 days) | 8,766 | 525,960 | 31,557,600 | 365.25 | 52.18 |
Base unit: milliseconds. Every calculation converts the input to milliseconds first, then converts from milliseconds to each target unit. This two-step approach keeps the code simple and accurate.
Fixed multipliers used: 1 second = 1,000 ms · 1 minute = 60,000 ms · 1 hour = 3,600,000 ms · 1 day = 86,400,000 ms · 1 week = 604,800,000 ms · 1 month = 2,629,800,000 ms (using 30.4375 days) · 1 year = 31,557,600,000 ms (using 365.25 days) · 1 decade = 315,576,000,000 ms.
Why 365.25 days per year? The Gregorian calendar averages one leap year every four years, adding 0.25 days to the mean year length. Using 365.25 gives accurate long-term averages, though specific years are either 365 or 366 days.
Why 30.4375 days per month? 365.25 ÷ 12 = 30.4375. Months in practice range from 28 to 31 days, so this is an average — useful for estimates, not for "exactly how many days until next payday."
How many seconds are in a year?
Using the standard 365.25-day year (which accounts for the leap year cycle), one year equals 31,557,600 seconds. The math: 365.25 × 24 × 60 × 60. For a non-leap year of exactly 365 days it's 31,536,000 seconds; for a leap year it's 31,622,400 seconds. The 31.557-million figure is the average most calculations use.
How do you convert decimal hours to hours and minutes?
Take the integer portion as whole hours. Multiply the decimal portion by 60 to get minutes. Example: 1.75 hours → the whole number is 1 hour, and 0.75 × 60 = 45 minutes → 1 hour 45 minutes. Another example: 2.333 hours → 2 hours, 0.333 × 60 = 20 minutes → 2 hours 20 minutes. This is critical for payroll, time tracking, and billing.
How do time conversions work for payroll?
Payroll systems record time in decimal hours because you can't multiply "7 hours 45 minutes" by a dollar amount — you need 7.75. The rule: divide minutes by 60 to get the decimal. So 15 min = 0.25 hrs, 30 min = 0.5 hrs, 45 min = 0.75 hrs. An 8-hour day, 5-day week, 52-week year gives the standard 2,080 hours used in annual salary calculations. Subtract paid holidays (typically 80–88 hours for 10–11 holidays) for actual working hours.
How many work hours are in a year?
The US standard is 2,080 work hours per year (8 hours × 5 days × 52 weeks). This is what most employers use for salary calculations and benefit prorations. If you subtract the average 10 federal holidays (80 hours) plus typical PTO of 10 days (80 hours), you arrive at roughly 1,920 actual productive hours per year — or about 40 weeks of real work. That gap matters when quoting annual project costs.
What are milliseconds used for in computing?
Milliseconds (1/1,000 of a second) are the standard unit for web performance metrics, API response times, and network latency. Human reaction time averages 200–250 ms. Google's research suggests page loads under 200 ms feel instant, 200–1,000 ms feel fast, and above 1,000 ms (one second) users start to disengage. Database queries are benchmarked in milliseconds; anything above 100 ms on a simple query usually signals an indexing problem. For even faster operations — CPU cycles, memory access — computing drops down to microseconds (µs) and nanoseconds (ns).